Lysophosphatidylcholine induces cyclooxygenase-2-dependent IL-6 expression in human cardiac fibroblasts

Abstract

Lysophosphatidylcholine (LysoPC) has been shown to induce the expression of inflammatory proteins, including cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6), associated with cardiac fibrosis. Here, we demonstrated that LysoPC-induced COX-2 and IL-6 expression was inhibited by silencing NADPH oxidase 1, 2, 4, 5; p65; and FoxO1 in human cardiac fibroblasts (HCFs). LysoPC-induced IL-6 expression was attenuated by a COX-2 inhibitor. LysoPC-induced responses were mediated via the NADPH oxidase-derived reactive oxygen species-dependent JNK1/2 phosphorylation pathway, leading to NF-κB and FoxO1 activation. In addition, we demonstrated that both FoxO1 and p65 regulated COX-2 promoter activity stimulated by LysoPC. Overexpression of wild-type FoxO1 and S256D FoxO1 enhanced COX-2 promoter activity and protein expression in HCFs. These results were confirmed by ex vivo studies, where LysoPC-induced COX-2 and IL-6 expression was attenuated by the inhibitors of NADPH oxidase, NF-κB, and FoxO1. Our findings demonstrate that LysoPC-induced COX-2 expression is mediated via NADPH oxidase-derived reactive oxygen species generation linked to the JNK1/2-dependent pathway leading to FoxO1 and NF-κB activation in HCFs. LysoPC-induced COX-2-dependent IL-6 expression provided novel insights into the therapeutic targets of the cardiac fibrotic responses.

Lysophosphatidylcholine-induced mitochondrial fission contributes to collagen production in human cardiac fibroblasts

“…The slices of cardiac apexes were pretreated with the inhibitors for 1 h, and then incubated with LPC for 6 h in Krebs solution (pH 7.4 at 37°C). The homogenates of cardiac apexes were prepared and lysed in a lysis buffer and subjected to Western blot analysis and RT-quantitative (q)PCR, as previously described (5).…”

“…The siRNA (100 nM) was added to each well, and then the cells were incubated at 37°C for 6 h. The cells were transferred to DMEM/F-12 medium containing 10% FBS for an additional 6 h, washed twice with PBS, and then maintained in serum-free DMEM/F-12 medium for 24 h before treatment with LPC. (S256D) FoxO1 mutant were cloned into the EcoRV-HindIII site of the pCMV-Tag2B vector, as previously described (5).…”

“…HCFs were seeded in 6-well plates or 10 cm dishes and after they reached 90% confluence, they were transferred to serumfree DMEM/F-12 medium and transiently transfected with plasmid DNA using an X-tremeGENE™ HP DNA transfection reagent (Roche Applied Science, Indianapolis, IN), as previously described (5).…”

Serum Metabonomic Study of Patients With Acute Coronary Syndrome Using Ultra-Performance Liquid Chromatography Orbitrap Mass Spectrometer

“…Lysophosphatidylcholine (LysoPCs) is a proinflammatory factor that leads to atherosclerosis (26). It is an important component of oxidized low-density lipoprotein (ox-LDL) and has a wide range of biological effects (27).…”

ASIC3-dependent metabolomics profiling of serum and urine in a mouse model of fibromyalgia

“…LysoPCs, as proinflammatory phospholipids, can generate superoxide anions in neutrophils 47 . Also, lysoPCs can activate the transcription factor NF-κB to regulate immune and inflammatory pathways and induce interleukin 8 (IL-8) and cyclooxygenase-2-dependent interleukin 6 (IL-6) expression and secretion 48,49 . Previous studies demonstrated higher serum IL-6 and IL-8 levels in FM patients than healthy controls 50,51 .…”